Sleeper arrangement for railroad switch

ABSTRACT

A track system has sleepers of predetermined width and at a predetermined spacing and a pair of running rails fixed to the sleepers. A switch has inner and outer transversely displaceable tongues engageable with the running rails and a pair of parallel hollow box sleepers of the predetermined width and at the predetermined spacing fixed to the running rails and on which the tongues are transversely displaceable. A drive rod extending transversely in one of the box sleepers is connected to both of the tongues so that a drive connected to the drive rod can transversely shift the tongues. Inner and outer position-monitoring rods extending transversely in the other of the box sleepers are connected to the respective guard rails.

FIELD OF THE INVENTION

[0001] The present invention relates to a railroad switch. More particularly this invention concerns a tie or sleeper arrangement for the rails, tongues, and operating mechanism for a railroad switch.

BACKGROUND OF THE INVENTION

[0002] A standard railroad switch comprises a pair of longitudinally extending running or stock rails that are fixed on transversely throughgoing ties or sleepers and that extend parallel to each other at a fixed transverse spacing. Respective tongue rails have ends displaceable transversely between a switching position meeting the respective running rails at a small acute angle at a so-called frog or point. When the tongues are in engagement with the respective running rails, as a train passes through the switch, its wheels will be diverted off onto the tongues and thence onto a siding or adjacent set of running rails. When out of engagement with the respective running rails, a train passing through the switch will continue on these running rails and not be diverted.

[0003] Since the positioning of these tongues is extremely critical, as an accident can result in disastrous destruction of property and loss of life, heavy-duty redundant systems are used that directly engage the rails and have three separate functions: actually transversely positioning the tongues, monitoring the actual positions of the tongues, and locking the tongues in place once they are determined to be properly positioned. Each of these functions is carried out by a separate mechanism that is associated with solid transversely extending structure that normally directly engages both of the tongue rails.

[0004] As described in U.S. Pat. No. 5,562,267 of Heim et al it is known to provide at a switch a so-called box sleeper which houses the various transverse rods used to set, monitor, and lock the transverse position of the tongues. Such a box sleeper itself is dimensioned like a standard sleeper and is spaced from the flanking sleepers by the standard spacing, about 600 mm. Since considerable equipment must be accommodated, it also extends substantially to both sides, taking up most of the space between itself and the adjacent sleepers.

[0005] This space is therefore not available for filling with ballast so that the box sleeper is not solidly held in position and vertical movement, so-called pumping, takes place when a train passes over the equipment-holding box sleeper. Furthermore the equipment that extends to both sides of the box sleeper prevents automated ballast-tamping devices to be used around the switch. The result is therefore considerable rail movement at the switch location leading to deformation of and damage to the switch parts, and additional difficulty and cost during standard tamping and maintenance of the rail bed.

OBJECTS OF THE INVENTION

[0006] It is therefore an object of the present invention to provide an improved sleeper arrangement for a railroad switch.

[0007] Another object is the provision of such an improved sleeper arrangement for a railroad switch which overcomes the above-given disadvantages, that is which accommodates the three main elements, namely the shifting rod, monitoring elements, and tongue-locking parts.

SUMMARY OF THE INVENTION

[0008] A track system has sleepers of predetermined width and at a predetermined spacing and a pair of running rails fixed to the sleepers. A switch according to the invention has inner and outer transversely displaceable tongues engageable with the running rails and a pair of parallel hollow box sleepers of the predetermined width and at the predetermined spacing fixed to the running rails and on which the tongues are transversely displaceable. A drive rod extending transversely in one of the box sleepers is connected to both of the tongues so that a drive connected to the drive rod can transversely shift the tongues. Inner and outer position-monitoring rods extending transversely in the other of the box sleepers are connected to the respective guard rails.

[0009] Thus with this system the rods and their associated structure are not all crowded into a single oversize box sleeper, but instead are distributed between a pair of box sleepers of standard width and spacing. As a result it is possible to provide ballast between them and to tamp it with conventional automatic equipment, ensuring that the sleepers in the switch are as well ballasted as the solid sleepers used elsewhere in the system, eliminating the pumping effect. The simple expedient of splitting up the various functions between two standard-size sleepers provides the considerable advantage of making it possible to use sleepers at the switch that can be ballasted and tamped like standard sleepers.

[0010] According to the invention a common housing is fixed transversely adjacent the box sleepers and into which the rods extend. A drive in the housing is connected to the drive rod, and position sensors in the housing are connected to the position-monitoring rods for determining the actual positions of the tongues.

[0011] The track system according to the invention further has a locking rod extending transversely in the other box sleeper and connected to both of the tongues and means in the housing connected to the locking rod for fixing the transverse position of the tongues. A link above the position-monitoring rods is fixed to and transversely interconnects the tongues. Respective inner and outer brackets connect outer ends of the inner and outer positioning rods to the respective tongues. The locking rod is slidable in the inner bracket has an outer end fixed to the link between the tongues. This link is a straight flat metal bar lying in a vertical and transverse plane and having bent ends fixed to the tongues. Respective inner and outer brackets connecting the bent ends to the inner and outer tongues.

[0012] Another link above the drive rod is fixed to and transversely interconnects the tongues and is fixed to an outer end of the drive rod. This link is also a straight flat metal bar lying in a vertical and transverse plane and having bent ends fixed to the tongues and respective inner and outer brackets connect the bent ends to the inner and outer tongues.

[0013] Each box sleeper in accordance with the invention has enlarged upper flanges to which the running rails are fixed. Chairs fixed to the tongues are slidable on the flanges. The floor of each box sleeper is provided with mounts for electric, hydraulic, or pneumatic control lines.

BRIEF DESCRIPTION OF THE DRAWING

[0014] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0015]FIG. 1 is a perspective view of the sleeper arrangement according to the invention;

[0016]FIG. 2 is a larger-scale top view of the switch structure of FIG. 1; and

[0017]FIGS. 3, 4, 5, 6, 7, 8, and 9 are sections taken along respective lines III-III, IV-IV, V-V, VI-VI, VII-VII, VIII-VIII, and IX-IX of FIG. 2.

SPECIFIC DESCRIPTION

[0018] As seen in FIGS. 1 and 2 a sleeper arrangement according to the invention comprises two hollow box sleepers 2 a and 2 b of a switch 1 and two standard solid sleepers 2 c that extend transversely between outer and inner longitudinally extending running rails 4 a and 4 b secured in place by standard clips 3 on the sleepers 2 a, 2 b, and 2 c. Outer and inner transversely displaceable and longitudinally extending tongues 7 a and 7 b are secured by clips 8 in chairs 5 slidable on flanges 6 of the sleepers 2 a and 2 b, although roller assemblies could be used to reduce friction. The sleepers 2 a-2 c are at a standard center-to-center spacing S of about 600 mm and are of a standard width W. While the sleepers 2 c are solid, normally of concrete or wood, as seen in FIGS. 2 through 9, the sleepers 2 a and 2 b are substantially identical and both formed of steel as upwardly open troughs with closed ends and inwardly turned edge flanges to which the clips 3 are secured. Spaces 29 between the sleepers 2 a through 2 c are filled with ballast, typically heavy gravel, and have standardized widths that are equal to the spacing S minus the width W. Normally the tops of the upwardly open box sleepers 2 a and 2 b are provided with covers having slots or other formations through which connection between the tongues 7 a and 7 b and the below-describe structure can pass.

[0019] The switch 1 has a motor housing 14 that is secured by fittings 15 to the inner ends of the sleepers 2 a and 2 b and that contains a drive mechanism 13, monitoring equipment 27, and locking equipment 28 respectively associated with a tongue-setting rod 9, a pair of position-monitoring rods 10 and 11, and a rod 12 that serves to lock the tongues 7 a and 7 b in position. The rod 9, which must exert considerable force on the transversely displaceable tongues 7 a and 7 b, is alone in the sleeper 2 b while the rods 10, 11, and 12 are all accommodated in the sleeper 2 a.

[0020] More particularly as shown in FIGS. 3, 4, 7, 8, and 9, the monitoring rods 10 and 11, which are associated with the monitoring equipment or sensors 27 in the housing 14, are connected via respective brackets 16 a and 16 b to the outer and inner tongue rails 7 a and 7 b so as to move synchronously therewith. The rod 10 passes through but is not connected to the inner bracket 16 b. Here the outer and inner brackets 16 a and 16 b are connected together by a link 17 constituted as a flat metal bar lying in a vertical plane and having right-angle ends 18 (FIG. 2) secured by bolts 21 to the brackets 16 a and 16 b. Thus the sensors or monitoring equipment 27 in the housing 13 can determine the actual positions of the tongue rails 7 a and 7 b, ensuring that each one is in where it should be.

[0021] As shown in FIGS. 5 and 7 through 9, the locking rod 12, which is associated with the locking mechanism 28, has an end 19 secured in a slide bracket or eye 20 fixed on the link 17, which lies above the rods 10, 11, and 12 which lie in a common horizontal plane. The rods 10, 11, and 12 are all accommodated in the box sleeper 2 a as mentioned above.

[0022]FIGS. 6 through 7 show how the outer end of the drive rod 9 is fixed between the rails 4 a and 4 b to a bracket 22 on a rigid metal link 23 having ends connected via brackets 24 a and 24 b to the rails 7 a and 7 b. Thus the link 23 locks the rails 7 a and 7 b together for joint transverse movement and connects them to the drive rod 9 which can be shifted by the drive mechanism 13 in the housing 14. Since the drive system incorporating the rod 9 and link 23 must transmit considerable force, these parts are relatively massive and are accommodated all alone in the box sleeper 2 b.

[0023] As shown in FIGS. 7 through 9, the box sleepers 2 a and 2 b have floors 25 to which cabling 26, for instance to heat the system and prevent ice from disabling it, and the like can be secured, below the transversely displaceable parts. 

I claim:
 1. In a track system having sleepers of predetermined width and at a predetermined spacing and a pair of running rails fixed to the sleepers, a switch comprising: inner and outer transversely displaceable tongues engageable with the running rails; a pair of parallel hollow box sleepers of the predetermined width and at the predetermined spacing fixed to the running rails and on which the tongues are transversely displaceable; a drive rod extending transversely in one of the box sleepers and connected to both of the tongues, whereby a drive connected to the drive rod can transversely shift the tongues; and inner and outer position-monitoring rods extending transversely in the other of the box sleepers and connected to the respective guard rails.
 2. The track system defined in claim 1, further comprising a common housing fixed transversely adjacent the box sleepers and into which the rods extend; a drive in the housing connected to the drive rod; and position-monitoring means in the housing connected to the position-monitoring rods for determining the actual positions of the tongues.
 3. The track system defined in claim 2, further comprising: a locking rod extending transversely in the other box sleeper and connected to both of the tongues; and locking means in the housing connected to the locking rod for fixing the transverse position of the tongues.
 4. The track system defined in claim 3, further comprising: a link above the position-monitoring rods and fixed to and transversely interconnecting the tongues; and respective inner and outer brackets connecting outer ends of the inner and outer positioning rods to the respective tongues, the locking rod being slidable in the inner bracket and having an outer end fixed to the link between the tongues.
 5. The track system defined in claim 4 wherein the link is a straight flat metal bar lying in a vertical and transverse plane and having bent ends fixed to the tongues.
 6. The track system defined in claim 5, further comprising: respective inner and outer brackets connecting the bent ends to the inner and outer tongues.
 7. The track system defined in claim 3, further comprising: a link above the drive rod, fixed to and transversely interconnecting the tongues, and fixed to an outer end of the drive rod.
 8. The track system defined in claim 7 wherein the link is a straight flat metal bar lying in a vertical and transverse plane and having bent ends fixed to the tongues.
 9. The track system defined in claim 8, further comprising: respective inner and outer brackets connecting the bent ends to the inner and outer tongues.
 10. The track system defined in claim 1 wherein each box sleeper has enlarged upper flanges to which the running rails are fixed.
 11. The track system defined in claim 10, further comprising: chairs fixed to the tongues and slidable on the flanges.
 12. The track system defined in claim 1 wherein each box sleeper has a floor provided with mounts for control lines. 